Sulfuric acid fumes escaping from the battery causes this corrosion.
The starter or battery cables/terminals are corrode.
Coating your car battery's positive and negative terminals with Vaseline will delay their natural inclination to corrode. It is a well known fact that sugar will corrode your teeth.
hydrogen gas being released from the acid in the battery. It mixes with other things in the atmosphere under the hood and produces the corrosion you see
The corrosion on the battery terminals is from the acid inside the battery. Baking soda neutralizes the acid so that it doesn't corrode the battery cables and the metal parts around the battery.
The function of battery terminals is to connect a load or charger to a cell battery. Battery terminals are necessary and common in a lot of batteries.
There are a few possibilities: Low battery, either because the alternator isn't keeping the battery charged or the battery is old and has failed. Corroded battery terminals, usually an indicator that the battery is blowing acid fumes. Batteries usually don't last long after the terminals start to corrode. Faulty starter solenoid. IT SOUNDS LIKE IT COULD BE YOUR STARTED CYLINOID
Corroded battery terminals, defective battery, or starter.Corroded battery terminals, defective battery, or starter.
Most battery terminals are made of lead.
on the battery
It could be as simple as a corroded battery terminal. Remove both battery terminals and clean them then see if it makes any difference. BTW, when a battery starts to corrode terminals it usually means that it's starting to vent some battery acid during the charge cycle. That's a sign that the battery is getting ready to go bad. It's probably still ok for now, but be ready for it to go out on you.
More than likely you have corrosion at the terminals. Clean the battery terminals and then recharge the battery and see what happens.
The battery acid is leaking out, either do to a failing battery or do to an alternator that is over charging.